Premature atherosclerosis is an emerging problem for patients with HIV infection who are treated with antiretroviral drugs. It is not clear whether these complications are related to HIV, the drugs, or the dyslipidemias that the drugs produce. A study has been developed to look at flow mediated dilation in patients with HIV treated with antiretroviral drugs. This technique is a surrogate for coronary artery disease that is well established, and is an assessement of endothelial function. In this study, groups of 20 treated antiretroviral treated patients with have their flow mediatied dilation measured, and then will be started on one of three consecutively enrolled arm including prevastatin and rosiglitazone. Patients will be assessed to determine if the intervention improved their flow mediated response, and whether other markers of endothelial cell function improve. The first arm is fully enrolled and has demonstrated surprisingly little effect of pravastatin.